Immune activation, whether occurring from direct immune checkpoint blockade or indirectly as a result of chemotherapy, is an approach that has drastically impacted the way we treat cancer. Utilizing patients' own immune systems for anti-tumor efficacy has been translated to robust immunotherapies; however, clinically significant successes have been achieved in only a subset of patient populations. Dendrimers and dendritic polymers have recently emerged as a potential nanocarrier platform that significantly improves the therapeutic efficacy of current and next-generation cancer immunotherapies. In this paper, we highlight the recent progress in developing dendritic polymer-based therapeutics with immune-modulating properties. Specifically, dendrimers, dendrimer hybrids, and dendronized copolymers have demonstrated promising results and are currently in pre-clinical development. Despite their early stage of development, these nanocarriers hold immense potential to make profound impact on cancer immunotherapy and combination therapy. This overview provides insights into the potential impact of dendrimers and dendron-based polymers, offering a preview of their potential utilities for various aspects of cancer treatment.